紫云英利用后减施化肥对水稻产量、产值及土壤碳氮含量的影响

摘要

通过大田定位试验，研究连续5年紫云英利用后不同化肥施用量对水稻产量和稻谷经济效益及土壤碳、氮含量的影响。设6个处理，处理 CK：不施紫云英和化肥(对照)；处理 CF：不施紫云英，施100%化肥(N、P2O5、K2O施用量分别为150、75、120 kg/hm2)；处理 A1：紫云英(22500 kg/hm2，下同)+100%化肥+100%磷肥；处理 A2：紫云英+80%氮、钾肥+100%磷肥；处理 A3：紫云英+60%氮、钾肥+100%磷肥；处理 A4：紫云英+40%氮、钾肥+100%磷肥。结果表明：施肥可以显著提高水稻产量，紫云英利用后化肥的增产效果更为显著，与CF相比，处理A2的早稻产量提高了7.7%，处理A3的水稻产量基本持平；紫云英利用后适当减少化肥用量可以增加水稻产值，与 CF相比，处理 A1的水稻产值增加了5.92%，处理A2的水稻产值增加效果次之，增加了4.08%；处理 A4提高水稻土壤有机碳和全氮含量的效果明显优于处理 CF，A2处理的土壤有机碳、全氮含量比 CF显著降低。%A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield, economic benefits of rice, soil car-bon(C) and total nitrogen (TN) under ploughing back of Chinese milk vetch for 5 consecutive years. Six treatments were included in the experiment, they are CK (unfertilized), CF (100% chemical fertilizer with the amount of N, P2O5, K2O being 150, 75, 120 kg/hm2 respectively), A1 (22 500 kg/hm2 Chinese milk vetch and 100%chemical fertilizer), A2 (Chinese milk vetch and 80% nitrogen and potassium fertilizer and 100% phosphate fertilizer), A3 (Chinese milk vetch and 60% nitrogen and potas-sium fertilizer and 100% phosphate fertilizer), A4 (Chinese milk vetch and 40% ni-trogen and potassium fertilizer and 100% phosphate fertilizer). The results were as fol ows: application of fertilizer could increase the yield of rice, while Chinese milk vetch combined with fertilizer application had a much more increase effect in rice yield. Under the condition of milk vetch application with 22 500 kg/hm2, the early rice yield of the treatment A1 was significantly increased by 7.7% compared with that of CF. And the yield of treatment A3 was basical y identical to or slight in-crease in comparison with that of CF. Decreasing amount of fertilizers cloud im-prove output value of rice in the case of the utilization of Chinese milk vetch. The treatment A1 increased output value of rice by 5.92% in comparison of CF, and treatment A2 was by 4.08% in the next. Treatment A4 showed much better effect in increasing soil organic carbon and total nitrogen in the paddy soil than those of treatments applying mineral fertilizer only. There was a significant reduction on soil organic carbon and TN in treatment A2 in comparison with that of CF. ln general, amount of application of milk vetch with 22 500 kg/hm2 could replace chemical fer-tilizer partial y, it also could improve rice yield, decrease the production cost, and raise the utilization efficiency of nutrients.